Search results for " surface"
showing 10 items of 2838 documents
The 2016 CEOS Infrared Radiometer Comparison: Part II: Laboratory Comparison of Radiation Thermometers
2019
AbstractTo ensure confidence, measurements carried out by imaging radiometers mounted on satellites require robust validation using “fiducial quality” measurements of the same in situ parameter. For surface temperature measurements this is optimally carried out by radiometers measuring radiation emitted in the infrared region of the spectrum, collocated to that of a satellite overpass. For ocean surface temperatures the radiometers are usually on board ships to sample large areas but for land and ice they are typically deployed at defined geographical sites. It is of course critical that the validation measurements and associated instrumentation are internationally consistent and traceable …
Molecular Engineering To Control the Magnetic Interaction between Single-Chain Magnets Assembled in a Two-Dimensional Network
2012
International audience; Two two-dimensional (2D) systems having the formula [{Fe-III(dmbpy)(CN)(4)}(2)(CoL)-L-II](n) [L = pyetNO (1), tvpNO (2)] and consisting of single-chain magnets connected through organic ligands (L) have been prepared, and their magnetic properties have been investigated. The overall magnetic behavior depends on the capacity of the organic pillars to transmit long-range magnetic interactions. 1 is the first example of a 2D compound exhibiting double relaxation of the magnetization, whereas 2 behaves as a metamagnet.
Contact laws between nanoparticles: the elasticity of a nanopowder
2018
International audience; Studies of the mechanical contact between nanometer-scale particles provide fundamental insights into the mechanical properties of materials and the validity of contact laws at the nanoscale which are still under debate for contact surfaces approaching atomic dimensions. Using in situ Brillouin light scattering under high pressure, we show that effective medium theories successfully predict the macroscopic sound velocities in nanopowders if one takes into account the cementation of the contacts Our measurements suggest the relevance of the continuum approach and effective medium theories to describe the contact between nanoparticles of diameters as small as 4 nm, i.e…
Magnetic Control over the Fractal Dimension of Supramolecular Rod Networks
2021
<p>Controlling supramolecular polymerization is of fundamental importance to create advanced materials and devices. Here we show that the thermodynamic equilibrium of Gd<sup>3+</sup>-bearing supramolecular rod networks is shifted reversibly at room temperature in a static magnetic field of up to 2 T. Our approach opens opportunities to control the structure formation of other supramolecular or coordination polymers that contain paramagnetic ions.</p>
Effets des émissions anthropiques de gaz à effet de serre sur le climat du bassin de l'océan Indien
2005
La simulation numérique du climat par le modèle couplé de circulation générale ARPEGE-OPA est utilisée ici pour prédire les effets d'un doublement du CO2 atmosphérique en l'an 2100 sur le climat du bassin de l'Océan Indien. Les températures de surface de la mer, les précipitations et les champs moyens de vents à 850 et 200 hPa sont étudiés au pas de temps trimestriel, sur les deux normales climatiques 1968-1997 et 2070-2099. Pour la fin du XX° siècle, le modèle a tendance à surestimer légèrement les TSM et plus fortement les précipitations, résultat d'un cycle hydrologique simulé trop développé. L'extraction d'indices pluviométriques calculés sur des régions homogènes montre que les télécon…
Impact de l'épandage des boues sur le phosphore dissous et particulaire des écoulements de surface
2003
Abstract The aim of this study was to assess the effect of land application of sewage sludge on phosphorus (P) losses during intense rainfall. Three rainfall simulations (40 mm h−1 of 30 min duration) were conducted on a field amended with sewage sludge. The overland flow water (OFW) was monitored and sampled every minute. The suspended solid, the dissolved and total phosphorus (respectively SS, TP and DP) concentrations were analysed. The forms of particulate bound P (PP) were investigated. Several results stem from this experiment: (a) sludge application induced a large increase in the DP content of the OFW; the concentrations obtained (0.15–0.57 mg l−1) were shown to result from desorpti…
Mapping intra-plot topsoil diversity of Burgundy vineyards (Aloxe- Corton, France) from very high spatial resolution (VHSR) images
2012
International audience; In this work, we present a method based on very high spatial resolution (VHSR) aerial images acquired in the visible domain and that map soil surface diversity at the hillslope scale with a spatial resolution of a few centimeters. This method combines aerial VHSR image classification with local soil sampling. Principal component analysis (PCA) and non-supervised classification was performed on image characteristics to define soil surface characteristic classes (SSC). Then soil surface mapping was combined with soil surface descriptions and soil profiles to define soil types by physical and chemical characteristics.
Sahel droughts and Enso dynamics
1996
Correlations between summer Sahel rainfall and Southern Oscillation Index has increased during the last thirty years. At high frequency time scale (periods lower than 8 years), an intertropical Atlantic zonal divergent circulation anomaly is forced by the difference of sea surface temperature (SST) anomalies between the eastern equatorial parts of Pacific and Atlantic. This zonal connection worked well during most of the E1 Nino/Southern Oscillation (ENSO) events occurring after 1970; positive/negative SST anomalies in the eastern Pacific/Atlantic led to rainfall deficits over the whole West Africa. At low frequency time scale (periods greater than 8 years), positive SST anomalies in the In…
Rainfall variability in subequatorial America and Africa and relationships with the main sea-surface temperature modes (1951–1990)
1995
The rainfall variability of subequatorial South America and Africa is poorly documented owing to the scarcity of data. We present a new land-only data set of monthly precipitation from 1951 to 1990, focusing on subequatorial South America and Africa, which improves the knowledge of rainfall variability and allows comparisons with GCM outputs. The results of multivariate analyses are compared with those performed on the best actual global rainfall data set developed by Mike Hulme. The main modes of bimonthly rainfall variability are not located in the major rain-forest basins of Za'ke and Amazonia, but rather on the tropical margins, such as Venezuela or Sudan, and near-coastal equatorial ar…
The Mistigri Thermal Infrared Project: Scientific Objectives And Mission Specifications
2013
ISI Document Delivery No.: 147NI Times Cited: 4 Cited Reference Count: 117 Cited References: Abrams M, 2000, INT J REMOTE SENS, V21, P847, DOI 10.1080/014311600210326 Agam N, 2007, J GEOPHYS RES-ATMOS, V112, DOI 10.1029/2007JD008407 Allen RG, 2007, J IRRIG DRAIN E-ASCE, V133, P380, DOI 10.1061/(ASCE)0733-9437(2007)133:4(380) Alletto L, 2006, CHEMOSPHERE, V64, P1053, DOI 10.1016/j.chemosphere.2005.12.004 Arnfield AJ, 2003, INT J CLIMATOL, V23, P1, DOI 10.1002/joc.859 Baschek B., 2010, 2010 OC SCI M PORTL Bastiaanssen WGM, 1998, J HYDROL, V212, P198, DOI 10.1016/S0022-1694(98)00253-4 Bastiaanssen WGM, 2005, J IRRIG DRAIN E-ASCE, V131, P85, DOI 10.1061/(ASCE)0733-9437(2005)131:1(85) Beck LR, 2…